Annular coke oven chamber with rotatable top charging hood and rotatable and movable coke discharge conveyor means



Oct. 27, 1970 KEIJI TSUJIHATA ETAL 3,536,590

ANNULAR COKE OVEN CHAMBER WITH ROTATABLE TOP CHARGING HOOD AND ROTATABLEAND MOVABLE COKE DISCHARGE CONVEYOR MEANS Filed March 14, 1966 5Sheets-Sheet 1 FIG! FIG. 2

:1 2e- 34 123 4 29 7 35 4 F 27-A MMWW ATTORNEY;

Oct. 27, 1970 KEIJI TSUJIHATA ETAL 3,536,590

ANNULAR COKE OVEN CHAMBER WITH ROTATABLE TOP CHARGING HOOD AND ROTATABLEAND MOVABLE COKE DISCHARGE CONVEYOR MEANS Filed March 14, 1966 3Sheets-Sheet 2 FIG. 3

INVENTORS BMW WMM ATTORNEYS Oct. 27, 1970 KEIJl TSUJIHATA ETAL 3,536,590

ANNULAR COKE OVEN CHAMBER WITH ROTATABLE TOP CHARGING HOOD AND ROTATABLEAND MOVABLE COKE DISCHARGE CONVEYOR MEANS Filed March 14. 1966 5Sheets-Sheet 5 F I G. 5

I NVENTOR WMM W ATTORNEYS United States Patent "ice Japan Filed Mar. 14,1966, Ser. No. 533,901 Claims priority, application Japan, Mar. 15,1965, 40/ 15,152 Int. Cl. Cb 7/02 US. Cl. 202117 5 Claims ABSTRACT OFTHE DISCLOSURE An apparatus for continuous baking of raw materials forproducing coke. A fixed annular furnace body having a continuous annularchamber for making raw material has an annular hood rotatably mountedabove it in air-tight engagement with the body. A charging device isprovided on top of said hood for charging material to be baked. Anexhaust gas discharging device is connected adjacent the top of saidannular furnace body. A conveying device is provided immediately underthe bottom annulus of said furnace body and is rotatable and movablearound the furnace body and spirally inclined downwardly in thedirection of rotation of the hood from an upper end to a lower endspaced in the direction of the annular furnace body from the upper end,and a material cutting device is provided just beyond the end of theconveying device at the lower end of the inclined conveying devicebetween the lower and upper ends and projecting upwardly from beneaththe level of the lower end of the conveying device and rotatable aroundthe furnace body with the conveyor for performing cutting action forcutting material from the bottom of a layer of baked material coming oifsaid conveying device.

This invention relates to an apparatus for continuously producing coke.

Most gas recovering type carbonization ovens for coke which haveheretofore been used as coke producing apparatus are noncontinuous.

Typical of them are the Nittetsu type (Japan), the Otto type and theKoppers type. In such conventional noncontinuous coke ovens (for examplea batch coke oven), when a coal charge has been dry-distilled in acarbonizing chamber so as to be converted to coke and th coke has beendischarged out of the chamber, because the oven is noncontinuous, thecarbonizing chamber will become empty and the temperature in thecarbonizing chamber will quickly fall. Further, when the emptiedcarbonizing chamber is charged with raw material, i.e. coal, the chamberwill be filled with the raw material coal at once, and the temperatureof the side wall of the carbonizing chamber will quickly fall to aboutthe temperature of the raw material. Therefore, the efficiency of theoperation will be greatly reduced.

Furthermore, in such a noncontinuous coke oven, the coal charged intothe carbonizing chamber from a charging port begins to be carbonizedonly by the heat transferred from the carbonizing chamber walls in thetraverse direction, and thus coking proceeds toward the center. When thecarbonization approaches its final stage, uncarbonized coal remains atthe center, extending in the vertical direction, and completecarbonization of the remaining vertical center portion of the coalrequires a long time. In this connection, by considering the coalcharged into the carbonizing chamber to be a fiat plate free from anychemical change and regarding the thermal conduc- 3,536,590 PatentedOct. 27, 1970 tion as a so-called unsteady one, in which the coaltemperature changes from a value 0a, to a higher value 60, the heatconduction can be expressed by Fouriers differential equation asfollows:

50/St=a(,9 0/Sx (1) where 0 is the temperature of the solid plate at aspot in question in degrees centigrade, t denotes a lapse of time inhours, x refers to a distance in the heat conducting direction, and a isthe thermal diffusivity in m. /hr. and equal to k/Cy, in which standsfor the thermal conductivity, C for the specific heat in Kcal./kg.C. and'y for the density in kg./cu.m.

The solution of the Equation 1 in the case of a semiindefinite solidbody, which is indefinitely long in the heat conducting direction, is:

and the solution in the case of a body of definite length is as follows:

1I=Q where V and V0 refer to the heat consumption in KcaL/ kg, s denotesa distance from a carbonizing chamber wall, 00 is the temperature of thecarbonizing chamber wall in degrees centigrade, and 0a stands for thetemperature of the charged coal in degrees centrigrade. The aboveformulated heat consumptions show that the nearer to the center (thefarther from the heat source) is a given coal portion is located, theslower the carbonization.

As will be understood from the above description, the heat conductionwhich is directed only from both sides to the center naturally requiresa long time (usually 16 to 24 hours), this making the operation markedlyinefficient.

The present invention provides a continuously operable cokemanufacturing apparatus of a cylindrical upright type which iscompletely different from the conventional non-continuous coke oven, andseeks mainly to effect a stable and continuous coking operation bycarbonizing coal in a thermally economical and always uniform state.

More particularly, this invention is characterized in that a rawmaterial layer is continuously spirally fed into an annular coke oven bymeans of a rotating raw material charging device so that thecross-section of the raw material body in the chamber is in the form ofa plurality of superposed portions and the carbonated layers aredrydistilled while the bottom layer is scraped off by means of a rotaryscraping device so that the raw material body continuously falls, thusgreatly enhancing coke productivity.

As described above, according to the present invention, above a fixedset annular or cylindrical upright coke oven is provide a rotary rawmaterial coal charging device for charging said coke oven with rawmaterial while rotating along said oven, and below said coke oven isprovided a rotary coke scraping device for scraping off completely bakedcoke. Thus, the apparatus of the present invention comprises the rotarycharging device and the scraping device provided above and below theannular or cylindrical upright coke oven, respectively.

An object of the present invention is to provide a continuous cokeproducing apparatus wherein raw material can be continuously fed,dry-distilled and baked into coke and then the coke can be continuouslyscraped ofl? and conveyed away.

Another object of the present invention is to provide an economicalcontinuous coke producing apparatus wherein coke can be produced at ahigh thermal efiiciency and a low producing cost.

A further object of the present invention is to provide a continuouscoke producing apparatus wherein good coke can be obtained from weakcaking coal and automation is easy.

The accompanying drawings illustrate an embodiment of the presentinvention.

FIG. 1 is a schematic perspective view of a coke producing apparatusaccording to the present invention.

FIG. 2 is a cross-sectional view on line AA of FIG. 3.

FIG. 3 is a plan view of the same embodiment.

FIG. 4 is a cross-sectional view of an oven body and a hood part of theapparatus of the present invention.

FIG. 5 is a cross-sectional view illustrating a sealing mechanism forthe apparatus of the present invention.

FIG. 6 is a detailed view showing the relation between the oven body anda conveying device.

In the present invention, a coal charge is continuously introduced inthe form of a layer into a carbonizing chamber by means of a rotarycharging device above a fixed cylindrical coke oven which is a featureof the present invention. In such case, the coal charge can becontinuously introduced in a pressed and molded form as circular grains,square grains, strips or fragmental strips. If such a pressing andmolding system is adopted, Weak caking coal can be easily utilized. Theshape of the overall cross-section of the raw material layer introducedis preferably square but can be rectangular, trapezoidal, semicircularor any other shape depending on the expansion, contraction and heattransmission at the time of distillation. The thus introduced coalcharge will be heated by radiation and conduction of heat from the brickwalls or the walls made of special heatproof cast steel plates defiiningthe carbonizing chamber which are heated to a red hot state and willbegin to be dry-distilled on the upper surface and on both sides. Thedry-distillation will begin also on the bottom surface due to the heattransmitted from the partially coked material in the lower layersintroduced during previous charging steps as coal and which has beenheated by radiation to a red hot state and already dry-distilled to aconsiderable degree.

On the other hand, the spirally extending and drydistilled charge on thebottom of the party is gradually scraped off by means of the rotaryscraping device. Therefore, the charge in the oven will gradually belowered. The layer deposited at the top corresponds substantially to thethickness of the charge layer scraped off the bottom. The distilledcharge on the bottom surface will have cooled to some extent. The gasproduced during the drydistillation will be sucked upward by making thepressure in a hood above the oven negative (about 2 mm. water).

The pressure in the hood is properly determined by the operatingconditions so that no air will be drawn in through the lower part of theoven and no gas produced in the oven will escape.

In the explanation of this invention, for the sake of brevity, a singleannular carbonizing chamber is used. But the number of the carbonizingchambers is not limited to one. A plurality of concentric annularchambers can be used. Usually, when about three chambers are provided,the productivity and economy will be highest.

In the conventional noncontinuous process, the capacity of the coke ovenis small and there have been great obstacles to the development of suchnew techniques as, for example, automation. On the other hand in thepresent invention, because the coke oven is continuous, the carbonizingconditions in the carbonizing chamber will be very uniform and a stableoperation can be achieved. Further, as heat is applied not only fromboth sides but also from the upper surface and the bottom surface asradiation, the carbonizing time will be greatly reduced, and aremarkable increase of efficiency can be achieved.

The present invention will now be explained more particularly withreference to the drawings. As illustrated in 4 FIGS. 1, 2 and 3, anupper rotary hood 2 is positioned over a fixed annular oven body 7 and acharging hopper 1 including a charging device is mounted therein. Wheels5 on shafts 6 on the hood 2 support the rotary hood 2 while running ontracks 31 supported on columns 29 positioned on the inside and theoutside of oven body 7.

An annular tube 3 for recovering distillation gases extends aroundfurnace body 7 and is supported on columns 10. Gas collecting pipes 12extend into the annular body from annular tube 3. An annular tube 4 forfuel gases extend around the inside and outside of annular furnace 7being supported on columns 10 by supports 23. Tube 33 feeds fuel to theinner tube 4 and a similar tube (not shown) feeds the outer tube 4.Conduit pipes 8 extend from annular tubes 4 to burners (not shown) inthe annular furnace body 7. A supporting metal piece 9 extends aroundfurnace body 7 and rests on supporting pillar supporting pillars 11 forholding the furnace body.

A rotary conveyor 13 runs around a tail drum 14 and a head drum 15 andextends around the bottom of the annular furnace body 7. A hopper 17 forreceiving coke scraped from the bottom layer in the annular furnace body7 is positioned between drums 14 and 15 and has a conveying pipe 18connected thereto. A coke scraper 16 is also positioned between drums 14and 15 and is iven in the direction of rotation of the head drum of theconveyor in the direction of arrow 39. The direction of the travel ofthe conveyer 13 is indicated by arrow 40. Within the annular furnacebody 7 is a continuous annular raw material charging chamber 30, and acontinuous annular carbonizing chamber 25 below it defined bycarbonizing chamber walls 26. Annular combustion chambers 24 extendthrough the furnace body 7 on each side of the carbonizing chamber 25.

FIGS. 4-6 show details of the various parts. The continuous chargingdevice for charging the coke oven of the present invention has a rawmaterial charging hopper 1 connected, for example, to a surging hopper.

A sealing means 35 between hood 2 and annular furnace body 7 comprisessealing plate 35A secured to the upper rotary hood 2 and a receivingchannel 35B secured to the oven body 7. The outer brick wall 27A of theannular oven body 7 has an outer cover 27B for the bricks. The tracks 31for Wheels 5 are supported on a support 34 on the outer cover 27B. Thestructure carrying the rotary scraping conveyer 13 includes wheels 19 ona shaft 12 on the lower member 28 'of a movable carriage 22. Wheels 19run on rails 32. On the back or inside surface of belt member 13A ofconveyer 13 are channel members 13B in which are engaged guide rails 13Cmounted on the top member 36 of the carriage 22 and which slide on theguide rails 13C so as to be guided around annular furnace body 7.Reinforcing frame members 37 are provided on the carriage 22. The returnrun of conveyor belt member 13a is supported on rollers 13D mounted onlower member 28. The upper run of belt member 13A is spirally inclineddownwardly from head drum 14 to tail drum 15.

In operation raw material fed into the charging hopper 1 illustrated inFIG. 1 will be gradually fed as the upper rotary hood 2 over the ovenbody is rotated in the direction indicated by the arrow. The amount ofmaterial charge can be adjusted. The fed raw material layer will bedeposited in the carbonizing chamber as the top spire of a continuousspiral of material extending in successive spires down through theannular carbonizing chamber, the top spire or layer having a thickness,for example, of about 0.4 meter.

As the carbonizing chamber walls 26 have been heated to a red-hot stateby the heat from the combustion chambers 24, the raw material fed intothe carbonizing chamber 25 will immediately begin to be dry-distilled.The bottom layer will be scraped off by the rotary scraping device afterit has been completely dry-distilled. It is desirable to taper thecarbonizing chamber 25 down wardly and outwardly to make it easy for thecharge in the carbonizing chamber to descend.

All the gases produced at the time of the dry-distillation will besucked upward and will be collected in the annular tube 3 through thegas collecting pipe 12. Because the pressure in the oven is madenegative, the high temperature dry-distillation gases will rise upward.Therefore, heat will be transmitted from the lower layers to the upperlayers and the advantage in the thermal efiiciency will be large.

On the other hand, not only will a newly introduced charge layer receiveheat transmitted by the rising gases, as is described above, but alsoits side surface layers will be heated to a red hot state by radiationfrom the carbonizing chamber walls 26 and will be dry-distilled to someextent. The top surface layer may already be red hot coke when the upperrotary hood 2 of the oven body brings the charging hopper 1 back to theoriginal charging position, Therefore, the next charge layer introducedonto said surface will receive heat on the bottom thereof and will beginto be preheated, dried and dry-distilled.

As described above, the layers will be dry-distilled by the radiationheat from the carbonizing chamber walls. Needless to say, both sides ofthe charge will be heated directly from the carbonizing chamber walls26. Therefore, the dry-distillation of the two sides will progress at avelocity higher than the upper and lower surfaces.

The dry-distillation progresses as described above and the successivelydeposited charge layers gradually descend to the final lowest layer andthe completed coke will be crushed and scraped olf by the rotation ofthe rotary scraping device 16. The conveyer 13 is driven along beneaththe furnace body 7 and supports the bottom layer of material in thefurnace body except where scraper 16 is located. The thickness which isscraped ofi can be, for example, 350 mm. but must be selected inrelation to the thickness of the charge layer.

It is desirable that the scraping position is somewhat ahead of thecharging position in the direction of rotation of the hood. This is toprevent fine vibrations occuring at the time of scraping from beingtransmitted to the charge layer but is not essential The crushed andscraped coke is discharged out of the oven and is conveyed as requiredto a cooling place or to a storing place in a plant using the coke.

In the present invention, if the height of the oven is made larger andthe number of the spires or layers in the spiral is increased asrequired the productivity will be able to be greatly increased. Needlessto say, if the diameter is made larger, the productivity will also beincreased but the thermal efficiency in such case will be lower than inthe former.

The recovered gases will be sent to the gas cooler through thedry-distillation gas recovering annular tube 3 and will be treated inthe same manner as in a conventional coke oven.

When it is necessary to dissipate gases, it will be possible todissipate them throughout the gas dissipating tube. The carbonizingchamber walls 26 are heated from the combustion of fuel gases in thecombustion chambers 24.

On the other hand, air for combustion is fed through the combustion airpipe, not illustrated in the drawing. Such combustion air can bepreheated with a heat-exchanger provided in the oven body. Needless tosay, a valve for regulating the amount of air is required so that theair for combustion can mix with the fuel gas.

The waste gas of the combustion in the combustion chamber 24 can beexhausted out of the oven through such heat-exchanger as is describedabove though not illustrated in the drawing.

The above described heat-exchanger is not essential. Even if it is notprovided, the object of the present invention will be able to be wellattained.

The present apparatus brings about great advantages (l) the coke ovenequipment cost is low relative to the cost of conventional equipment forthe same amount of production,

(2) because the system is continuous, the thermal efficiency is high,

(3) only a relatively small space is required for the layout,

(4) because it is possible to continuously feed raw material pressed andmolded as required, it is easy to utilize weak caking coal (5) becausethe amount of production of the gas is always uniform, smoke generationcan be easily prevented and (6) automation is easy.

It contributes also to the reduction of costs.

In the present invention, because the raw material charging device isrotatable above the fixed coke oven body and the rotary scrapingconveyer is provided in the bottom part of the oven, as compared withsuch rotary coke ovens previously and developed as a continuous cokeproducing apparatus of this kind, not only can the power for chargingthe oven with raw material be greatly reduced but also the oven wallbricks will be less damaged. Further, as the fed coal will be stationaryuntil it is coked, it is possible to obtain coke high in strength. Asthe fuel feeding system is entirely fixed, there is an advantage thatthe feeding path is simpler.

What is claimed is:

1. An apparatus for continuous baking of raw materials for producingcoke which apparatus comprises, in combination, a fixed annular furnacebody having a continuous annular chamber for baking raw material, an annular hood rotatably mounted above said annular furnace body in airtightengagement with the body, a device on top of said hood for chargingmaterial to be baked, a further device connected adjacent the top ofsaid annular furnace body for discharging the exhaust gas produced bybaking raw material, a conveying device provided immediately under thebottom annulus of said furnace body and rotatable and movable around thefurnace body and being spirally inclined downwardly in the direction ofrotation of the hood from an upper end to a lower end spaced in thedirection of the annular furnace body from the upper end, and a materialcutting device provided just beyond the end of the conveying device atthe lower end of the inclined conveying device between the lower andupper ends and projecting upwardly from beneath the level of the lowerend of the conveying device and rotatable around the furnace body withthe conveyor for performing cutting action for cutting material from thebottom of a layer of baked material coming oif said conveying device.

2. An apparatus as claimed in claim 1 in which said furnace body hasannular combustion chambers therein on each side of said annular bakingchamber, said combustion chambers being elongated in the verticaldirection.

3. An apparatus as claimed in claim 2 in which said baking chamber isdownwardly and outwardly tapered.

4. An apparatus as claimed in claim 1 in which said hood has a pluralityof wheels thereon, and rails forming part of said apparatus andextending around said annular furnace body on which said wheels run.

5. An apparatus as claimed in claim 1 in which said conveyor devicecomprises a conveyor belt having an upper run extending along the bottomof the annular furnace body, a carriage on which said conveyor belt ismounted, said carriage having wheels thereon, rails extending around theapparatus beneath the furnace body on which the carriage runs, and guidemeans on said carriage engaged by the upper run of said belt and guidingsaid belt along the bottom of said annular furnace body.

(References on following page) 7 8 References Cited 3,302,936 2/1967 Ban26621 UNITED STATES PATENTS 3,370,937 2/1968 Tsujihata et a1. 266-201,698,348 1/1929 Puening 202-262 FOREIGN PATENTS 1,861,876 6/1932Puening 202-262 r 1,146,045 11/1957 France. 1,908,538 5/1933 Puening202-115 1,346,891 11/1963 France- 11929132 10/1933 Winzer WILBUR L.BASCOMB, JR., Primary Examiner 2,091,702 8/1937 Daniels 202 1153,006,816 10/1961 Finney 202-262 10 3,199,850 8/1965 Lee 266-21 202115,126, 133, 262; 2-01-40; 26621

